#!/usr/bin/env elixir

Mix.install([
  {:jason, "~> 1.0"}
])

%{"source_files" => data} =
  "cover/excoveralls.json"
  |> File.read!()
  |> Jason.decode!()

{total_covered, total_total} =
  data
  |> Enum.reduce({0,0}, fn %{"coverage" => cover}, {covered, total} ->
    file_covered =
      cover
      |> Enum.reduce(0, &(if is_integer(&1) && &1 > 0, do: &2 + 1, else: &2))

    file_total =
      cover
      |> Enum.reduce(0, &(if is_nil(&1), do: &2, else: &2 + 1))

    {covered + file_covered, total + file_total}
  end)

ratio =
  (total_covered / total_total)
  |> Float.round(3)

File.write!("metrics.txt", "coverage #{ratio}")